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International Journal of Aerospace Engineering
Volume 2013 (2013), Article ID 590924, 13 pages
http://dx.doi.org/10.1155/2013/590924
Research Article

Numerical Simulation of Airfoil Aerodynamic Penalties and Mechanisms in Heavy Rain

Beijing University of Aeronautics and Astronautics, Beijing 100191, China

Received 19 July 2013; Revised 21 September 2013; Accepted 22 September 2013

Academic Editor: N. Ananthkrishnan

Copyright © 2013 Zhenlong Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Numerical simulations that are conducted on a transport-type airfoil, NACA 64-210, at a Reynolds number of and LWC of 25 g/m3 explore the aerodynamic penalties and mechanisms that affect airfoil performance in heavy rain conditions. Our simulation results agree well with the experimental data and show significant aerodynamic penalties for the airfoil in heavy rain. The maximum percentage decrease in is reached by 13.2% and the maximum percentage increase in by 47.6%. Performance degradation in heavy rain at low angles of attack is emulated by an originally creative boundary-layer-tripped technique near the leading edge. Numerical flow visualization technique is used to show premature boundary-layer separation at high angles of attack and the particulate trajectories at various angles of attack. A mathematic model is established to qualitatively study the water film effect on the airfoil geometric changes. All above efforts indicate that two primary mechanisms are accountable for the airfoil aerodynamic penalties. One is to cause premature boundary-layer transition at low AOA and separation at high AOA. The other occurs at times scales consistent with the water film layer, which is thought to alter the airfoil geometry and increase the mass effectively.